1. Field of the Invention
The present invention relates to the field of handheld digital devices. More specifically, the present invention relates to the placement of data entry keys with respect to the display within each of these devices.
2. Background Information
Advances in computer and telecommunication technology have led to the wide spread adoption and miniaturization of electronic organization and communication devices, such as personal digital assistants (PDAs) and wireless pagers. Although smaller versions of such devices allow increased portability, the reduction in size is typically accompanied by awkward keypad positioning thereby hindering one's ease of use and possibility causing discomfort to the user.
FIG. 1 illustrates an exemplary prior art PDA. As illustrated, prior art PDA 100 typically includes body-casing 116 with top end 118A, bottom end 118B, left side 119A and right side 119B, as well as keypad 102, disposed near bottom end 118B. Keypad 102 represents a set of small, fingertip-sized data entry keys configured in a standard “QWERTY” arrangement to facilitate a user in providing numeric and/or alphanumeric input into PDA 100. Keypad 102 further includes functions keys 120-121, which are linked to pre-programmed functions such as character mode and/or operating mode switching activated by the press of the appropriate function keys 120-121 by a user.
PDA 100 further includes display screen 108, which is disposed near top end 118A above keypad 102, and is used to echo numeric or alphanumeric inputs entered by a user, as well as to display various graphical and/or alphanumeric messages, menu options, control information, status information, and so forth. For example, display screen 108 is illustrated as displaying graphical icons 110-114, and date and time information 104.
Although the physical size of body casing 116 may vary, PDA 100 is typically palm-sized so as to fit within the palm of an average user's hand. During normal use, by virtue of its configuration with keypad 102 disposed near bottom end 118B and display screen 108 disposed near top end 118A above keypad 102, a user will typically rest body casing 116 on one or both of their index fingers formed into an arch with at least one of the user's thumbs being utilized to pinch PDA 100 against the arched forefinger(s), thus leaving only one of the users thumb free to enter and/or manipulate data via keypad 102. Accordingly, the user typically severely arches their thumbs into an inconvenient and uncomfortable position in order to operate PDA 100, thereby exposing the user to possible discomfort. Furthermore, due to keypad 102 being disposed below display screen 108, display screen 108 is rendered vulnerable to bright light sources such as the sun. In situations where display screen 108 represents a backlit display for example, such bright light shone on display screen 108 can severely interfere with the users viewing of information displayed within display screen 108.
Therefore, a more user-friendly design, in particular, one that improves thumb manipulability of the keypad is desired.